File fix-build.patch of Package opencity

diff --git a/src/guicontainer.cpp b/src/guicontainer.cpp
index 65a8ac0..52fba82 100644
--- a/src/guicontainer.cpp
+++ b/src/guicontainer.cpp
@@ -17,6 +17,7 @@
  *                                                                         *
  ***************************************************************************/
 
+#include <GL/glu.h>
 // Useful enumerations
 #include "opencity_direction.h"
 #include "opencity_structure_type.h"
diff --git a/src/renderer.cpp b/src/renderer.cpp
index 599a6ac..444bfa7 100644
--- a/src/renderer.cpp
+++ b/src/renderer.cpp
@@ -51,6 +51,7 @@ for the first time:
 //========================================================================
 
 #include <climits> // need for UINT_MAX
+#include <GL/glu.h>
 
 // Useful enumerations
 #include "opencity_direction.h"
diff --git a/src/texture.cpp b/src/texture.cpp
index da88afd..a72021a 100644
--- a/src/texture.cpp
+++ b/src/texture.cpp
@@ -17,6 +17,8 @@
  *                                                                         *
  ***************************************************************************/
 
+#include <GL/glu.h>
+
 // Useful enumerations
 #include "opencity_direction.h"
 #include "opencity_structure_type.h"
diff --git a/viewer/viewer.cpp b/viewer/viewer.cpp
index 1a9cea2..b412c46 100644
--- a/viewer/viewer.cpp
+++ b/viewer/viewer.cpp
@@ -14,6 +14,7 @@
     - mine type for .ac
 */
 
+#include <GL/glu.h>
 // Useful enumerations
 #include "opencity_direction.h"
 #include "opencity_structure_type.h"